<< Chapter < Page Chapter >> Page >

Determine the normal boiling point (in kelvin) of dichloroethane, CH 2 Cl 2 . Find the actual boiling point using the Internet or some other source, and calculate the percent error in the temperature. Explain the differences, if any, between the two values.

Got questions? Get instant answers now!

Under what conditions is N 2 O 3 ( g ) NO ( g ) + NO 2 ( g ) spontaneous?

The reaction will be spontaneous at temperatures greater than 287 K.

Got questions? Get instant answers now!

At room temperature, the equilibrium constant ( K w ) for the self-ionization of water is 1.00 × 10 −14 . Using this information, calculate the standard free energy change for the aqueous reaction of hydrogen ion with hydroxide ion to produce water. (Hint: The reaction is the reverse of the self-ionization reaction.)

Got questions? Get instant answers now!

Hydrogen sulfide is a pollutant found in natural gas. Following its removal, it is converted to sulfur by the reaction 2H 2 S ( g ) + SO 2 ( g ) 3 8 S 8 ( s , rhombic ) + 2H 2 O ( l ) . What is the equilibrium constant for this reaction? Is the reaction endothermic or exothermic?

K = 5.35 × 10 15
The process is exothermic.

Got questions? Get instant answers now!

Consider the decomposition of CaCO 3 ( s ) into CaO( s ) and CO 2 ( g ). What is the equilibrium partial pressure of CO 2 at room temperature?

Got questions? Get instant answers now!

In the laboratory, hydrogen chloride (HCl( g )) and ammonia (NH 3 ( g )) often escape from bottles of their solutions and react to form the ammonium chloride (NH 4 Cl( s )), the white glaze often seen on glassware. Assuming that the number of moles of each gas that escapes into the room is the same, what is the maximum partial pressure of HCl and NH 3 in the laboratory at room temperature? (Hint: The partial pressures will be equal and are at their maximum value when at equilibrium.)

1.0 × 10 −8 atm. This is the maximum pressure of the gases under the stated conditions.

Got questions? Get instant answers now!

Benzene can be prepared from acetylene. 3C 2 H 2 ( g ) C 6 H 6 ( g ) . Determine the equilibrium constant at 25 °C and at 850 °C. Is the reaction spontaneous at either of these temperatures? Why is all acetylene not found as benzene?

Got questions? Get instant answers now!

Carbon dioxide decomposes into CO and O 2 at elevated temperatures. What is the equilibrium partial pressure of oxygen in a sample at 1000 °C for which the initial pressure of CO 2 was 1.15 atm?

x = 1.29 × 10 5 atm = P O 2

Got questions? Get instant answers now!

Carbon tetrachloride, an important industrial solvent, is prepared by the chlorination of methane at 850 K.
CH 4 ( g ) + 4Cl 2 ( g ) CCl 4 ( g ) + 4HCl ( g )

What is the equilibrium constant for the reaction at 850 K? Would the reaction vessel need to be heated or cooled to keep the temperature of the reaction constant?

Got questions? Get instant answers now!

Acetic acid, CH 3 CO 2 H, can form a dimer, (CH 3 CO 2 H) 2 , in the gas phase.
2CH 3 CO 2 H ( g ) ( CH 3 CO 2 H ) 2 ( g )

The dimer is held together by two hydrogen bonds with a total strength of 66.5 kJ per mole of dimer.

This Lewis structure shows a six-sided ring structure composed of a methyl group single bonded to a carbon, which is double bonded to an oxygen atom in an upward position and single bonded to an oxygen atom in a downward position. The lower oxygen is single bonded to a hydrogen, which is connected by a dotted line to an oxygen that is double bonded to a carbon in an upward position. This carbon is single bonded to a methyl group to its right and to an oxygen in the upward position that is single bonded to a hydrogen that is connected by a dotted line to the double bonded oxygen on the left.

At 25 °C, the equilibrium constant for the dimerization is 1.3 × 10 3 (pressure in atm). What is Δ S ° for the reaction?

−0.16 kJ

Got questions? Get instant answers now!

Nitric acid, HNO 3 , can be prepared by the following sequence of reactions:
4NH 3 ( g ) + 5O 2 ( g ) 4NO ( g ) + 6H 2 O ( g )
2NO ( g ) + O 2 ( g ) 2NO 2 ( g )
3NO 2 ( g ) + H 2 O ( l ) 2HNO 3 ( l ) + NO ( g )

How much heat is evolved when 1 mol of NH 3 ( g ) is converted to HNO 3 ( l )? Assume standard states at 25 °C.

Got questions? Get instant answers now!

Determine Δ G for the following reactions.

(a) Antimony pentachloride decomposes at 448 °C. The reaction is:
SbCl 5 ( g ) SbCl 3 ( g ) + Cl 2 ( g )

An equilibrium mixture in a 5.00 L flask at 448 °C contains 3.85 g of SbCl 5 , 9.14 g of SbCl 3 , and 2.84 g of Cl 2 .

(b) Chlorine molecules dissociate according to this reaction:
Cl 2 ( g ) 2 Cl ( g )

1.00% of Cl 2 molecules dissociate at 975 K and a pressure of 1.00 atm.

(a) −22.1 kJ;
(b) 61.6 kJ/mol

Got questions? Get instant answers now!
Practice Key Terms 3

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Ut austin - principles of chemistry. OpenStax CNX. Mar 31, 2016 Download for free at http://legacy.cnx.org/content/col11830/1.13
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Ut austin - principles of chemistry' conversation and receive update notifications?

Ask